title: Selective extraction of strontium with supercritical fluid carbon dioxide.
abstract: Strontium (Sr(2+)) can be selectively extracted from aqueous solutions into supercritical fluid CO(2) at 60 °C and 100 atm with dicyclohexano-18-crown-6 (DC18C6) using CF(3)(CF(2))(6)CO(2) (-) (PFOA(-)) or CF(3)(CF(2))(6)CF(2)SO(3) (-) (PFOSA(-)) as a counter anion; at a mole ratio of Sr(2+) : DC18C6 : PFOA(-) = 1:10:50, the extraction of Sr (5.6 × 10(-5) M) from water at pH 3 is near quantitative whereas Ca(2+) and Mg(2+) at equal concentration are only extracted to a level of 7 and 1%, respectively; PFOSA(-) is an effective counter anion for selective extraction of Sr(2+) from 1.3 M HNO(3) with DC18C6 in supercritical CO(2).
authors.affiliation: Department of Chemistry, University of Idaho, Moscow, ID 83844, USA.
authors.forename: Chien M
authors.initials: CM
authors.lastname: Wai
authors.forename: Yurii
authors.initials: Y
authors.lastname: Kulyako
authors.forename: Hwa-Kwang
authors.initials: HK
authors.lastname: Yak
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
authors.forename: Suh-Jane
authors.initials: SJ
authors.lastname: Lee